The long-term objective of this project is to demonstrate that hypervious fluids are efficacious in the treatment and improved survival from traumatic hemorrhagic shock. It is proposed to develop a treatment for hypovolemic cardiovascular collapse based on the infusion of high viscosity plasma expanders, which provide a novel small-volume resuscitation that recovers microvascular perfusion for extended periods until surgical control of bleeding is possible. The central hypothesis is that in conditions of hypotension, and cardiovascular collapse, high viscosity plasma restores moderate levels of mean arterial blood pressure needed to ensure open capillaries and tissue perfusion. Our data shows that open capillaries are critical to tissue survival, and viscogenic plasma expanders with tailored oncotic pressure properties restore microvascular function and rescue the organism from hypovolemic cardiovascular collapse. In the case of uncontrolled bleeding, these solutions provide limited-volume resuscitation with maximum microvascular perfusion and a gradual increase in blood pressure thereby minimizing re-bleeding, leading to important savings of blood transfusions, providing a new approach for dealing with conditions in which reduced tissue perfusion jeopardizes tissue survival in field conditions. In this project, a microcirculatory assessment in the hamster window preparation will be used with sophisticated and state of the art measurements of macro and microhemodynaimcs, including local pO2 levels, capillary pressure, and nitric oxide release. The properties of a transfusion fluid in terms of viscosity and oncotic properties which best recovers cardiovascular collapse will be identified in a lethal uncontrolled bleeding model.